The specific aims of this proposal are to evaluate three possible methods of adjuvant therapy in combination with partial ileal bypass surgery in rabbits. The three methods are: (1) dietary adjuvants, using either alfalfa-enriched diet or a sucrose polyester containing diet; (2) pharmacologic adjuvants, using compactin (or mevinolin), probucol, or gemfibrozil; and (3) continuous intra-portal venous infusion of natural metabolites, using either sodium deoxycholate or glucagon. The possible adjuvant substances will be studied independently and in combination with partial ileal bypass. We will explore the methods of action of these possible adjuvants by determining the following parameters: plasma total cholesterol, triglycerides, and lipoprotein fractions cholesterol concentrations; cholesterol absorption, excretion, and turnover; bile acid excretion and turnover; hepatic cholesterol and bile acid cholesterol and bile acid synthesis rates. We hope to be able to understand better the mechanisms of action of these several substances in order to advance our capacity to intervene with therapy based upon knowledge rather than supposition. The purpose of these combined therapy studies is to find a method, or methods, of enhancing the powerful plasma lipid and lipoprotein modifications of partial ileal bypass, with the eventual goal of providing a method of reducing all hyperlipoproteinemic patients' plasma lipids to satisfactory levels.